on certain socket 7 mainboards, there is a jumper for setting CPU CLK pin voltage to either 5V or 3.3V, and that jumper is on 5V by default. now, according to the datasheet, that pin is indeed 5V tolerant on pentiums up to P54CS, so it shouldn't be an issue.

however, what is the point of this jumper in the first place when there weren't any 5V CPUs for socket 7, and one would think they could have just hardwired it to 3.3V? or did any of the other manufacturers' CPUs require 5V on that pin?